Koyo crankshaft special for crank applications, Koyo developed -9T cages which have a black
appearance. These have a special coating that provides increased
strength and aids lubrication under severe conditions normally found in
2 stroke motorcycles.
They alsohave special heat treated inner or outer rings to double bearing
life by hardened resistance to wear from insufficient or contaminated
lubrication.

Used to replace Yamaha 93306-30633-00.